In a process for manufacturing a semiconductor device, a photolithography technology is used. In the photolithography technology, a resist is coated upon a surface of a semiconductor wafer (hereinafter referred to as a "wafer"), the coated resist is exposed to a predetermined pattern and then developed. Thus, a resist film with a predetermined pattern is formed upon the wafer. And then, a circuit with a predetermined pattern is formed by film-forming and etching treatment.
Conventionally, such series of resist processing is performed using a coating and developing system where a plurality of units such as a resist coating unit, a developing unit and a heating unit are disposed integrally.
The heating unit has a hot plate disposed in the center for heating a target object such as a semiconductor wafer. A plurality of support pins appear from and disappear into the hot plate for receiving and delivering the wafers. A shutter member, also appearing and disappearing, is disposed around the hot plate surrounding the hot plate. Conventionally, only the inside of the shutter member was exhausted.
However, there has been a problem that the volatilized solvent filling the closed space formed by the shutter member leaks outside when the shutter member descends after the heating process, giving ill influence to other processes.